1. Field of the Invention
The present invention relates to an integrated passive device, and more particularly, to an integrated passive device with an electrostatic discharge protection mechanism.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a diagram showing an electrostatic discharge protection mechanism of an integrated passive device. The integrated passive device 100 is a duplexer filter. The integrated passive device 100 comprises an antenna terminal 110, a first frequency terminal 120, a first filtering circuit 130, a second frequency terminal 140, and a second filtering circuit 150. The antenna terminal 110 is for receiving and transmitting a wireless signal. The first frequency terminal 120 is for receiving and transmitting a signal with a first frequency, such as a signal with a 2 GHz frequency. The second frequency terminal 140 is for receiving and transmitting a signal with a second frequency, such as a signal with a 5 GHz frequency. The first filtering circuit 130 comprises capacitor and inductor elements for filtering the wireless signal for allowing the signal with the first frequency to be received by the first frequency terminal 120. The second filtering circuit 150 also comprises capacitor and inductor elements for filtering the wireless signal for allowing the signal with the second frequency to be received by the second frequency terminal 140. As shown in FIG. 1, in order to prevent the capacitor elements of the first filtering circuit 130 and the second filtering circuit 150 from being damaged by static electricity, an electrostatic discharge protection element 160 is electrically connected to the antenna terminal 110. The electrostatic discharge protection element 160 comprises a plurality of diodes electrically connected to each other in series for conducting the static electricity to ground.
Please refer to FIG. 2. FIG. 2 is a diagram showing an electrostatic discharge protection mechanism of another integrated passive device. The integrated passive device 200 is a harmonic filter. The integrated passive device 200 comprises an antenna terminal 210, a predetermined frequency terminal 220, and a filtering circuit 230. The antenna terminal 210 is for receiving and transmitting a wireless signal. The predetermined frequency terminal 220 is for receiving and transmitting a signal with a predetermined frequency, such as a signal with a 2.5 GHz frequency. The filtering circuit 230 comprises capacitor and inductor elements for filtering the wireless signal for allowing the signal with the predetermined frequency to be received by the predetermined frequency terminal 220. Similarly, as shown in FIG. 2, in order to prevent the capacitor elements of the filtering circuit 230 from being damaged by the static electricity, an electrostatic discharge protection element 260 is electrically connected to the antenna terminal 210. The electrostatic discharge protection element 260 comprises a plurality of diodes electrically connected to each other in series for conducting the static electricity to ground.
However, according to the above arrangement, the diodes electrically connected to each other in series form a parasitic capacitor, and further affect frequency responses of the filtering circuits 130, 150, 230. For example, the frequency responses of the filtering circuits 130, 150, 230 cannot meet design values at higher frequency. The above arrangements of the electrostatic discharge protection elements of the prior art affect frequency responses of the filtering circuits of the integrated passive devices, such that the frequency responses of the integrated passive devices can not meet design requirements.